1988 XJS V12 Lister 5-Speed manual conversion to SBC - Help
#1
1988 XJS V12 Lister 5-Speed manual conversion to SBC - Help
Hello all,
As a long-time Jaguar enthusiast, I recently came into possession of a 1988 XJS V12 with the Lister mod (body kit and 5-Speed Getrag manual transmission). She's a beauty! Unfortunately, the original owner overheated the engine and blew the motor. I plan to convert the car to a small-block Chevy -- probably an LT1 from a mid-90s vehicle. I'm hoping that some of you with experience can provide some much-needed advice.
I've been told that I can and should re-use the getrag 5-speed (and I would very much like to keep it). I *think* I have found the appropriate adapter kit to mate the getrag to the chevy small block here: https://www.aksportscars.co.uk/media...or-kit-jaguar/
But I've also been told that I shouldn't keep the getrag because it won't handle the power put out by the V8, and that it would be difficult and cost-prohibitive to re-use it and that I should instead use the complete drivetrain from a manual V8 donor car.
Does anyone have experience with this? If the adapter I linked will work, and the getrag will indeed take the power of the V8, I would prefer to keep it. If popular opinion is that keeping it is ill-advised, I will likely re-consider.
Also, does anyone have experience with specific kits for these conversions? I'm aware of John's Cars, as well as Jaguar Specialties. Can anyone comment on advantages and/or disadvantages of going with either company?
I realize that many here are Jaguar purists and the thought of replacing the V12 with a SBC is horrible, but with the original motor blown, it would require a complete rebuild or replacement with a new V12 which would need to be maintained, either of which are cost-prohibitive to me. Sorry.
I really appreciate any advice you can offer. As I understand it, this car is rare and unique - I hope you enjoy the photos. I'm excited at the prospect of driving it soon.
Sean
As a long-time Jaguar enthusiast, I recently came into possession of a 1988 XJS V12 with the Lister mod (body kit and 5-Speed Getrag manual transmission). She's a beauty! Unfortunately, the original owner overheated the engine and blew the motor. I plan to convert the car to a small-block Chevy -- probably an LT1 from a mid-90s vehicle. I'm hoping that some of you with experience can provide some much-needed advice.
I've been told that I can and should re-use the getrag 5-speed (and I would very much like to keep it). I *think* I have found the appropriate adapter kit to mate the getrag to the chevy small block here: https://www.aksportscars.co.uk/media...or-kit-jaguar/
But I've also been told that I shouldn't keep the getrag because it won't handle the power put out by the V8, and that it would be difficult and cost-prohibitive to re-use it and that I should instead use the complete drivetrain from a manual V8 donor car.
Does anyone have experience with this? If the adapter I linked will work, and the getrag will indeed take the power of the V8, I would prefer to keep it. If popular opinion is that keeping it is ill-advised, I will likely re-consider.
Also, does anyone have experience with specific kits for these conversions? I'm aware of John's Cars, as well as Jaguar Specialties. Can anyone comment on advantages and/or disadvantages of going with either company?
I realize that many here are Jaguar purists and the thought of replacing the V12 with a SBC is horrible, but with the original motor blown, it would require a complete rebuild or replacement with a new V12 which would need to be maintained, either of which are cost-prohibitive to me. Sorry.
I really appreciate any advice you can offer. As I understand it, this car is rare and unique - I hope you enjoy the photos. I'm excited at the prospect of driving it soon.
Sean
#2
Get an LT1 with a T56. T56 is a much better transmission and you get an extra gear. Adapters can cause all sorts of problems vibrations misalignments and unknown issues I would never use any sort of adapter unless it was a well-developed product that was known to work properly. You should be able to sell that Getrag transmission, clutch and bell housing to someone else and recover most of what you paid for an LT1 with a T56.
Last edited by icsamerica; 10-25-2018 at 11:21 PM.
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samwathegreat (10-25-2018)
#3
i would second a t56 if you really want to use the original trans a stock lt1 is going to be very similar horsepower to the v12 so if your not planning to modify the 350 the getrag shouldn't be under much additional strain. if you are going to swap it though i would suggest selling your stock transmission, tons of people would love to have a manual behind there v12, would probably sell for more than your t56 setup would cost. and wouldn't have any adapter plate problems and a better transmission.
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samwathegreat (10-25-2018)
#4
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samwathegreat (10-25-2018)
#5
#6
#7
Lovely car, exactly the same colour as my XJS. Whats under the bonnet there? Any Lister upgrades or is it stock engine? Wouldnt it cost similar money to put another, fully working, V12 in there and make the whole thing much easier? Plus I'm sure a V12 would fully pay for itself back when you get to selling it at some point in the future, conversion on the other hand, wont.
T56 would surely cost as much as another V12, with the rest of the Jag attached to it, so probably a nono if costs are an issue?
T56 would surely cost as much as another V12, with the rest of the Jag attached to it, so probably a nono if costs are an issue?
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#8
I agree with the keeping it V12 if it's a genuine Lister.
When you say the PO blew the motor what is broken if it's dropped valve seat and hammered a piston to death you can buy another V12 and rebuild the original motor keeping it numbers matching. If it needs more pistons and liners Norman Lutz sells 94mm bore kits for about $4000AUD turning the 5.3L into a 6.0L
When you say the PO blew the motor what is broken if it's dropped valve seat and hammered a piston to death you can buy another V12 and rebuild the original motor keeping it numbers matching. If it needs more pistons and liners Norman Lutz sells 94mm bore kits for about $4000AUD turning the 5.3L into a 6.0L
#9
#10
I am certainly not a purist by any means, but man, a Lister? Would you want to swap it?
I've rebuilt 3 Jag V12s now, and although very time consuming, The V12 would be less expensive to rebuild than any conversion. Just because the PO overheated it, doesn't mean that the engine is bad. I've done all my own work, and with a little luck, even if you've got a dropped valve seat, if you are handy with wrenches, and are patient, you just "may" repair/rebuild the V12 for under 4K. I know from experience you will spend more than that converting the car. Nothing quite like a well running V12.
I've rebuilt 3 Jag V12s now, and although very time consuming, The V12 would be less expensive to rebuild than any conversion. Just because the PO overheated it, doesn't mean that the engine is bad. I've done all my own work, and with a little luck, even if you've got a dropped valve seat, if you are handy with wrenches, and are patient, you just "may" repair/rebuild the V12 for under 4K. I know from experience you will spend more than that converting the car. Nothing quite like a well running V12.
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Flint Ironstag (05-22-2023)
#11
#12
Hey Indiana !
I live in Northeast Arkansas, about the bootheel of Missouri. I may be able to solve your problem, as I have an 89 XJS, I bought for the wiring harness, as My original 89 had an engine fire. So now I have 2 - 89's, one with a good running v12. I'm lumping my original 89, so I have the good V12 for sale. I'd take $800.00 cash and carry. If interested let me know. I'd be glad to help.
Jack
I live in Northeast Arkansas, about the bootheel of Missouri. I may be able to solve your problem, as I have an 89 XJS, I bought for the wiring harness, as My original 89 had an engine fire. So now I have 2 - 89's, one with a good running v12. I'm lumping my original 89, so I have the good V12 for sale. I'd take $800.00 cash and carry. If interested let me know. I'd be glad to help.
Jack
#13
I understand why people lump their jags but I have to agree with the above posts. Listers are some of the rarest of the rare here in the states.. Not only would sourcing a V12 be cheaper and easier than doing a swap, (especially since Jacobra is already offering one up), it would retain the car's value and collectability. There're plenty of cheap, normal xjs/xj6/xj12's out there ripe for a sbc swap but for such a rare and collectible car to lose its soul would be a shame.
The V12's scare people more than they should. If you have the expertise to do an engine swap, you have the expertise to keep the V12 up and running (especially with the help of the brilliant folks on this forum). They can actually be very reliable with just a few common trouble spots addressed. And for what it's worth, the V12's are like nothing else on the road, the difference between a sbc and the factory engine is night and day. (ESPECIALLY with that manual!) You wouldn't regret it.
The V12's scare people more than they should. If you have the expertise to do an engine swap, you have the expertise to keep the V12 up and running (especially with the help of the brilliant folks on this forum). They can actually be very reliable with just a few common trouble spots addressed. And for what it's worth, the V12's are like nothing else on the road, the difference between a sbc and the factory engine is night and day. (ESPECIALLY with that manual!) You wouldn't regret it.
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Flint Ironstag (05-22-2023)
#14
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ronbros (11-01-2018)
#16
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#17
Well, that was a bust; wrote a load of stuff and posted three pictures and only one came out.
Anyway; wheel badge script doesn't look quite right (to me), rear bumper doesn't look right, no Lister front bumper, no Lister badge on Bonnet.
I'm not saying it isn't a Lister because they did make bespoke ones; just saying to be careful, especially if trying to sell it.
I'll try another couple of pictures of my old one; this had non-standard script on it too, just in case you were wondering what it was that just went screaming past you.
Anyway; wheel badge script doesn't look quite right (to me), rear bumper doesn't look right, no Lister front bumper, no Lister badge on Bonnet.
I'm not saying it isn't a Lister because they did make bespoke ones; just saying to be careful, especially if trying to sell it.
I'll try another couple of pictures of my old one; this had non-standard script on it too, just in case you were wondering what it was that just went screaming past you.
#18
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#19
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#20
Join Date: Jul 2010
Location: Austin tx and Daytona FL.
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back in late 1990s Lister brought a Lister STORM race car for the Daytona 24 HR race , it was a respectable performer, but an OFF at chicane damaged suspension , altho at that time turbo cars were comin on strong,who knows what , it had an encredable sounding V12 !
i had some pictures but when computer was in for some cleaning , dumb kid cleaned everything out! Duh.
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Flint Ironstag (05-22-2023)